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> SOS SIDE OF ROAD, LJet help
r_towle
post Jul 25 2008, 04:21 PM
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Side of road, dead car.
74 Ljet
New tank of gas.
Fuel pump and fuel pressure good (check by opening door on AFC with key on)
Spark at coil good (plug direct to coil)
Spark at plug good...same test, ran from plug wire.

Removed a plug..its dry.

Seems like the injectors are not firing...what makes Ljet injectors fire?
What can be tested?

I have a meter with me etc..I drove here with my tools.

Need Diagnostics NOW

Rich
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dr914@autoatlanta.com
post Jul 25 2008, 04:35 PM
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QUOTE(r_towle @ Jul 25 2008, 03:21 PM) *

Side of road, dead car.
74 Ljet
New tank of gas.
Fuel pump and fuel pressure good (check by opening door on AFC with key on)
Spark at coil good (plug direct to coil)
Spark at plug good...same test, ran from plug wire.

Removed a plug..its dry.

Seems like the injectors are not firing...what makes Ljet injectors fire?
What can be tested?

I have a meter with me etc..I drove here with my tools.

Need Diagnostics NOW

Rich
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Cevan
post Jul 25 2008, 04:57 PM
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Sounds like a question for Ed. I believe the injectors get power via the dual relay (terminal 88b) thru the resistor pack. Check the relay. It looks like when the coil gets power, it activates the relay and powers the injectors.
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ejm
post Jul 25 2008, 05:39 PM
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QUOTE
I believe the injectors get power via the dual relay (terminal 88b) thru the resistor pack.


Correct. You should have power at the center terminal of the resistor pack. The injectors are grounded individually by the control unit. White wire on control unit sends rpm signal to the control unit, the injectors pulse won't without it.

So did George get you going?
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dr914@autoatlanta.com
post Jul 25 2008, 05:42 PM
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so rich we talked did you get it going??
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r_towle
post Jul 25 2008, 07:01 PM
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Nope, I ended up doing a few tests with Brad on the phone...still no dice.

Just gonna eat dinner and hook up the trailer. I can go through the whole thing when I get home.

I have power at the injectors. I took them out (the passenger side pair) and turn over the car while holding the flapper door open to get the fuel pump going...they do spray, but not alot.
I think my son messed up something with the fuel lines....

the lines look right at the pump, but he ran out of gas several times lately so I am starting to think fuel filter...
From left to right on the pump I have return, pressure and suction.
They are still hooked up the way I did it.

I am going to put it up on stands and start at the tank to verify that my son has not flipped something or kinked something...
Its just not getting enough fuel...

Rich
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Brando
post Jul 25 2008, 09:10 PM
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sounds like plugged injectors (if they're firing).

Dual relay good?

Resistor Pack good?

Did any of the wires on the bottom of the dual relay come out? They're prone to doing that.

Points good?
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Rav914
post Jul 25 2008, 09:19 PM
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Fuel filter like you mentioned also. Could be choked on particles.
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wertygrog
post Jul 25 2008, 09:41 PM
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Oh God, what did Abel do this time? (IMG:style_emoticons/default/smile.gif)

Funny my dad blames things on me too haha. (IMG:style_emoticons/default/smile.gif)

good luck on the repair!
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Bartlett 914
post Jul 26 2008, 08:10 AM
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Autohausaz has injectors on sale still. I replaced all 4 of mine and my car runs like new. If yours turn out to be plugged, new ones would be better than having the old ones cleaned. I know this doesn't help on the side of the road but I thought I would throw this in anyway. Lots of luck.

Injectors on sale
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Rocket
post Jul 26 2008, 11:24 AM
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hey guys, so i pulled out the battery today and cleand all the acid off with baking soda and water. when i was down there, after taking of the computer, i found a green wire that is not plugged into anything. right behind the comptuer, just laying in the hell hole. any idea what this little green wire is? and what does it do?
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type47
post Jul 26 2008, 01:25 PM
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QUOTE(Rocket @ Jul 26 2008, 09:24 AM) *

a green wire that is not plugged into anything. right behind the comptuer, just laying in the hell hole. any idea what this little green wire is? and what does it do?


sounds like the connector for the wire to the oil temperature sender/"taco" plate sender. check to see if the wire is actually green/black. if you can, test continuity to the plugs for the connection to the console, you can check a wiring diagram (pelican has one) to get the color code of the oil temp wire. you don't say what the year of your car or engine but there are model year production cars that have the wiring in place for a console (73-> ?).
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r_towle
post Jul 26 2008, 11:06 PM
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End of story...

Fuel line have fallen of twice or more in the last month.
Last time I think he ran out of gas due to fuel line falling off.
This apparently, and as far as I can guess, burned out the fuel pump by running it dry.
It did run for a few days after the last event, but its a 34 year old pump...so the strain of running dry killed it.

yes we have talked about the fuel line and potential for a fire...
Yes, I know.
The end result was a new fuel pump solved the problem.
I learned all about Ljet...how to diagnose it...I like it better than Djet now...its simpler...

Rich
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r_towle
post Jul 27 2008, 08:57 AM
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Well,
My sons Ljet died on the side of the road.
I called George Hussey, Brad, and got on the internet asking for help, and the team of 914 experts came through.
Ljet diagnosis was new for me...at least a catastrophic failure.

We had spark.
We had fuel...we had injector timing and all of them were firing...hmmm
Once Brad explained to me how the firing was done...it was simple to test.

It ended up being a dead fuel pump...or a dying one.
It was only producing 10psi...nothing I could figure out on the side of the road.

We trailered it home and checked the fuel system front to back.
My son did all of the work while I was dropping my daughter at camp...so I was on the road for 10 hours.
A few phone calls from him...a fuel pressure test in two places and we figured it was the pump.
The kid is turning into quite a mechanic. He did a systematic round of testing every system...really nice to have him know all of this.

Sure enough..he harvested a pump from the parts car and he was good to go.
My son did some great work figuring this out...I was just a phone support guy.
Brad was a great help, several phone calls with details for different tests.
ED, thanx for the elec test explanation...that ruled out the relays with a few simple tests.

George, thanx for being there and answering the phone...what a guy.

Rich
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Katmanken
post Jul 27 2008, 09:29 AM
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Yeah, those Bosch pumps should never be run dry- the fuel is the lubricant.

Killls them every time.

And it's not a problem with just the L-jet.

KennyWithaDaughterWhoUsedToLikeToRunOutofGas
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drewvw
post Jul 27 2008, 04:48 PM
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ironic...since you helped me out with my fuel pump issue this morning
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MartyYeoman
post Jul 28 2008, 02:50 PM
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QUOTE(Bartlett 914 @ Jul 26 2008, 07:10 AM) *

Autohausaz has injectors on sale still. I replaced all 4 of mine and my car runs like new. If yours turn out to be plugged, new ones would be better than having the old ones cleaned. I know this doesn't help on the side of the road but I thought I would throw this in anyway. Lots of luck.

Injectors on sale


(IMG:style_emoticons/default/agree.gif)

I took advantage of this sale and WOW what an improvement.
I should have replaced my injectors years ago.
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jd74914
post Jul 28 2008, 03:24 PM
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Now, take the pump apart and look @ the pressure regulator (if that is what you can call it, its really the bypass thing) with the spring in it. I fixed my pump by diassembling it and replacing the spring in there from another pump with a roasted motor. It turned out that a few of the pumps I had appeared broken because this spring had worn out and could not handle the pressure.

Hopefully that makes some sense. In my case the the pump with replaced spring has worked well in my car for the past few months. (Knock on wood).
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rick 918-S
post Jul 28 2008, 03:46 PM
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Sheeze, good thing you didn't have to wait for my help, I just saw this post.. (IMG:style_emoticons/default/screwy.gif) Glad your running.
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r_towle
post Jul 28 2008, 06:51 PM
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QUOTE(rick 918-S @ Jul 28 2008, 05:46 PM) *

Sheeze, good thing you didn't have to wait for my help, I just saw this post.. (IMG:style_emoticons/default/screwy.gif) Glad your running.


LOL

Rich
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